The Signal Hill, California-based company started out about 10 years ago doing various special projects, such as demo cars, for General Motors. After completing a Cadillac project around three years ago, D3 decided to run a pilot program to find out if there was a market out there for a dedicated Cadillac tuner by modifying an STS. Upon finding there indeed was an unfilled niche, D3 embarked on more projects, although it skipped the CTS-V because other companies had a head start on its LS-series engines, moving on to the STS-V, XLR, and XLR-V instead.According to D3 vice president of sales and marketing James Gill, the company doesn't start with a laundry list of parts it wants to develop, but instead spends the time to research the individual model to learn its strengths and weaknesses. One example is the STS-V, which has a small coolant reservoir that needed to be beefed up. Cosmetic modifications are designed with the goal of retaining the Cadillac feel, so there are no ridiculous body kits or wheels. Currently, Gill says, D3 offers the largest variety of Cadillac aftermarket parts in the world.

D3's latest project is a supercharger for the direct-injected 3.6L V-6 powering the 2009 Cadillac CTS that should make around 400 hp and will slot neatly between the stock 300-hp engine and the 556-hp 6.2L V-8 of the CTS-V. D3 also plans to do extensive work on the CTS-V as well as the upcoming CTS Coupe and, should one be made, the CTS-V Coupe.D3 has maintained a close relationship with GM. The automaker provides it Cad designs as well as technical and engineering data, which in turn helps D3 develop better components. GM even came out to D3's recent "Cadillac Performance Event" at Auto Club/California Speedway in Fontana, California, bringing a pair of 2009 CTS-Vs (one of which set the now-famous 7:59 lap time around the Nurburgring) along with Speed World Challenge GT factory Cadillac pilot Andy Pilgrim.

Currently, D3 employs about 20 people with orders coming from across the country as well as overseas from places like Dubai. All design and development is done in house, though some production work like machining is currently outsourced. The company plans to move into a bigger facility in the not too distant future and bring all its operations in house.To see what D3 has to offer, visit its Web site at: www.d3cadillac.com